1. Field of the Invention
This invention relates generally to electronic camera modules, and more particularly to miniature, digital camera modules. Even more particularly, this invention relates to a design for a miniature camera module that can host electronic components without increasing the overall size of the camera module.
2. Description of the Background Art
Digital camera modules are currently being incorporated into a variety of host devices. Such host devices include cellular telephones, personal data assistants (PDAs), computers, and so on. Consumer demand for digital camera modules in host devices continues to grow.
Host device manufacturers prefer digital camera modules to be small, so that they can be incorporated into the host device without increasing the overall size of the host device. Further, host device manufacturers prefer camera modules that minimally affect host device design. In meeting these requirements the host device manufacturers prefer camera modules that capture images of the highest possible quality. Of course, it is an ongoing goal for camera module manufacturers to design camera modules that meet these requirements at minimal manufacturing cost.
A conventional digital camera module generally includes a lens assembly, a housing, a printed circuit board (PCB), and an integrated circuit image capture device (ICD). Typically, the components are formed separately and later assembled to create the digital camera module. That is, the ICD is attached to the PCB, and then the housing is attached to the PCB so that the ICD is covered by the bottom of the housing. Then, the lens assembly is mounted to the opposite end of the housing to focus incident light onto an image capture surface of the ICD. The ICD is electrically coupled to the PCB, which includes a plurality of electrical contacts for the ICD to communicate image data to the host device for processing, display, and storage.
In order to make such camera modules more attractive to host device designers, manufacturers have added various designs and features. For example, it is common for a camera module to include a variable focus/zoom device for enhancing the quality of images captured at various focal fields. Typically, the variable focus/zoom device includes an electronic actuator coupled to one or more lenses of the lens assembly for displacing the lens(s) with respect to the image capture surface of the ICD and with respect to each other. In addition to variable focus/zoom devices, it is common for such camera modules to include a larger ICD with a greater numbers of photosensitive diodes to further increase the image quality. Also, many camera modules include other components (e.g., memory chips, processors, resistors, capacitors, inductors, etc.) that would otherwise be located on the host device. This is a desirable feature because host device designers prefer camera modules that operate independently from the host device so as to minimally impact the overall design of the host device.
Although a variable focus/zoom feature, larger ICD, and integrated electronic components add desirable features, the addition of such features increases the overall size of the camera module. Of course, this increase in size is undesirable to host device manufacturers.
In efforts to decrease the overall size of such camera modules without sacrificing image quality, manufacturers have developed many different designs and features. For example, camera module manufacturers can form the housing and/or other components over any electronic components which may already be fixed to the PCB, by molding the housing directly over the electronic components.
Although incorporating the electronic components within the walls of the housing decreases the overall size of the camera module, disadvantages still exist. For example, the number of electronic components is limited by the size of the camera module.
What is needed, therefore, is a compact camera module that is capable of capturing images of higher quality while taking up minimum space. What is also needed is a camera module that operates more independently from the host device. What is also needed is a camera module that minimally impacts the overall design of the hosting device. What is also needed is a camera module that can host more components without increasing the camera modules overall size.